Polycarbonate based resin composition and molded articles thereof

ABSTRACT

The present invention relates to a polycarbonate based resin composition and molded articles thereof, and more particularly, to a polycarbonate based resin composition of which impact strength, flowability (fluidity), and the like, are improved, and molded articles thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2014-0173005 filed in the Korean IntellectualProperty Office on Dec. 4, 2014, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a polycarbonate based resin compositionand molded articles thereof, and more particularly, to a polycarbonatebased resin composition of which impact strength, flowability(fluidity), and the like, are improved, and molded articles thereof.

BACKGROUND ART

Polycarbonate resins are prepared by condensation-polymerization of anaromatic diol such as bisphenol A with a carbonate precursor such as aphosgene and have excellent impact strength, dimensional stability, heatresistance, transparency, and the like. Thus, the polycarbonate resinshave application in a wide range of uses, such as exterior materials ofelectrical and electronic products, automobile parts, buildingmaterials, optical components, and the like.

Recently, in order to apply these polycarbonate resins to more variousfields, many studies have been made to obtain desired physicalproperties by copolymerizing two or more aromatic diol compounds havingdifferent structures from each other and introducing units havingdifferent structures in a main chain of the polycarbonate. In addition,studies for introducing a polysiloxane structure in a main chain of thepolycarbonate have been undergone, but most of these technologies havedisadvantages in that when a specific physical property is improved, butother physical properties are deteriorated.

Meanwhile, recently, as a necessity for forming a thin film using thepolycarbonate resin has increased, a demand for a polycarbonate basedresin having high flowability (fluidity) during a melting process andthus having excellent melt-processability, or a composition thereof hasincreased. In addition, recently, requirements for various physicalproperties such as chemical resistance, impact strength, or the like,required in the polycarbonate resin have further increased.

However, generally, in the case of further improving chemicalresistance, impact strength, or the like, of the polycarbonate basedresin or the composition thereof, flowability may be deteriorated, suchthat it is difficult to sufficiently achieve thin-film moldability andmelt-processability. Therefore, it was difficult to satisfy highflowability and melt-fluidity to exhibit excellent thin-filmmoldability, or the like, while having excellent chemical resistance,impact strength, and the like, required in the polycarbonate basedresin.

Therefore, a polycarbonate based resin of which impact strength such aslow-temperature impact strength, or the like, flowability (fluidity),melt-processability, and the like, are simultaneously improved, or acomposition thereof has been continuously required.

DISCLOSURE Technical Problem

The present invention has been made in an effort to provide apolycarbonate based resin composition having advantages of improvedimpact strength, flowability (fluidity), processability, and the like.

The present invention has been made in an effort to provide moldedarticles containing the polycarbonate based resin composition.

An exemplary embodiment of the present invention provides apolycarbonate based resin composition comprising: a copolycarbonateresin including a repeating unit represented by the following ChemicalFormula 1, a repeating unit represented by the following ChemicalFormula 3, and a repeating unit represented by the following ChemicalFormula 4; and a first polycarbonate resin including a repeating unitrepresented by the following Chemical Formula 2:

in Chemical Formula 1,

R₁ to R₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, orhalogen, and,

Z₁ is C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, C₃₋₁₅cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO,SO₂, or CO,

in Chemical Formula 2,

R₅ to R₁₂ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, orhalogen,

Z₂ and Z₃ are each independently C₁₋₁₀ alkylene unsubstituted orsubstituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted orsubstituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO, and

A is C₁₋₁₅ alkylene,

in Chemical Formula 3,

each of X₁ is independently C₁₋₁₀ alkylene,

each of R₁₃ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted orsubstituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

n is an integer of 10 to 200,

in Chemical Formula 4,

each of X₂ is independently C₁₋₁₀ alkylene,

each of Y₁ is independently hydrogen, C₁₋₆ alkyl, halogen, hydroxy, C₁₋₆alkoxy, or C₆₋₂₀ aryl,

each of R₁₄ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted orsubstituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

m is an integer of 10 to 200.

Another exemplary embodiment of the present invention provides moldedarticles containing the polycarbonate based resin composition.

Hereinafter, polycarbonate based resin compositions according toexemplary embodiments of the present invention and molded articlesthereof will be described in more detail.

Technical terms used herein are only to describe a specific embodiment,and do not limit the present invention. In addition, singular forms usedin the present specification include plural forms as long as they do nothave clearly different meanings.

Further, the term ‘include’ or ‘contain’ used in the presentspecification is to specify a specific property, region, integer, step,operation, factor, and/or component, but dose not exclude presence oraddition of another specific property, region, integer, step, operation,factor, component, and/or group.

According to the exemplary embodiment of the present invention, there isprovided a polycarbonate based resin composition comprising acopolycarbonate resin including a repeating unit represented by thefollowing Chemical Formula 1, a repeating unit represented by thefollowing Chemical Formula 3, and a repeating unit represented by thefollowing Chemical Formula 4; and

a first polycarbonate resin including a repeating unit represented bythe following Chemical Formula 2:

in Chemical Formula 1,

R₁ to R₄ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, orhalogen, and

Z₁ is C₁₋₁₀ alkylene unsubstituted or substituted with phenyl, C₃₋₁₅cycloalkylene unsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO,SO₂, or CO,

in Chemical Formula 2,

R₅ to R₁₂ are each independently hydrogen, C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, orhalogen,

Z₂ and Z₃ are each independently C₁₋₁₀ alkylene unsubstituted orsubstituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted orsubstituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO, and

A is C₁₋₁₅ alkylene,

in Chemical Formula 3,

each of X₁ is independently C₁₋₁₀ alkylene,

each of R₁₃ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted orsubstituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

n is an integer of 10 to 200,

in Chemical Formula 4,

each of X₂ is independently C₁₋₁₀ alkylene,

each of Y₁ is independently hydrogen, C₁₋₆ alkyl, halogen, hydroxy, C₁₋₆alkoxy, or C₆₋₂₀ aryl,

each of R₁₄ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted orsubstituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, and

m is an integer of 10 to 200.

The first polycarbonate resin may selectively further include arepeating unit repeating unit represented by Chemical Formula 1 inaddition to the repeating unit represented by Chemical Formula 2. Therepeating unit represented by Chemical Formula 1 may have a structureequal to or different from that of the repeating unit represented byChemical Formula 1, included in the copolycarbonate resin.

As described above, the resin composition according to the exemplaryembodiment may include both of the first polycarbonate resin having therepeating unit represented by Chemical Formula 2, including an aliphaticalkylene A group and the copolycarbonate resin including specificpolysiloxane group-containing repeating units represented by ChemicalFormulae 3 and 4, together with the repeating unit represented byChemical Formula 1, which is a repeating unit of a general aromaticpolycarbonate. The first polycarbonate resin and a second polycarbonateresin to be described below may be distinguished from thecopolycarbonate resin in that a polysiloxane structure is not introducedin a main chain in the first and second polycarbonate resins, but isintroduced in a main chain in the copolycarbonate resin as in ChemicalFormulae 3 and 4. Hereinafter, unless particularly described, the firstand second polycarbonate resins and the copolycarbonate resin may bedistinguished and defined as described above.

The first polycarbonate resin having the repeating unit represented byChemical Formula 2 may allow the resin composition according to theexemplary embodiment to have higher flowability (fluidity) by containingthe repeating unit having the aliphatic group A. Further, as a result ofcontinuous experiments by the present inventors, it was confirmed thatthe copolycarbonate resin having the repeating units represented byChemical Formulae 3 and 4 may allow the resin composition according tothe exemplary embodiment to have improved impact strength (particularly,low-temperature impact strength) and chemical resistance and a lowyellow index (YI) value by containing a specific polysiloxane group.

Therefore, it was confirmed that as the resin composition according tothe exemplary embodiment simultaneously include the first polycarbonateresin and the copolycarbonate resin, which have these specific repeatingunit structures, the resin composition may have excellent flowabilityand melt-fluidity to thereby have excellent thin-film moldability, andthe molded articles thereof may have excellent chemical resistance,excellent impact strength such as low-temperature impact strength, orthe like, and a low YI value. Therefore, the resin composition accordingto the exemplary embodiment may solve problems of polycarbonate basedresins known in the art, or the like, and be suitably applied to variousfields and uses in which excellent physical properties, and thin-filmmolding are required.

Hereinafter, each of the components capable of being included in thepolycarbonate based resin composition according to the exemplaryembodiment of the present invention will be described in detail.

(1) Copolycarbonate Resin

The copolycarbonate resin, which is a component capable of improvingphysical properties of an existing aromatic polycarbonate resin,particularly, impact strength, chemical resistance, a YI value, and thelike, may be included in the resin composition according to theexemplary embodiment. The copolycarbonate resin may include therepeating unit represented by Chemical Formula 1, which is a basicrepeating unit of an aromatic polycarbonate based resin, and therepeating units represented by Chemical Formulae 3 and 4, having aspecific polysiloxane unit.

First, the repeating unit represented by Chemical Formula 1, which forma basic backbone of the copolycarbonate resin, may be formed by areaction of an aromatic diol compound and a carbonate precursor. Therepeating unit represented by Chemical Formula 1 as described above mayalso be included to first and second polycarbonate resins to bedescribed below, and the repeating unit represented by Chemical Formula1, included in the copolycarbonate resin may have a structure equal toor different from that of the repeating unit represented by ChemicalFormula 1, included in the first and second polycarbonate resins.

In Chemical Formula 1, R₁ to R₄ may be each independently, hydrogen,methyl, chloro, or bromo.

Further, Z₁ may be preferably a linear or branched C₁₋₁₀ alkyleneunsubstituted or substituted with phenyl, and more preferably,methylene, ethane-1,1-diyl, propane-2,2-diyl, butane-2,2-diyl,1-phenylethane-1,1-diyl or diphenylmethylene. In addition, Z₁ may bepreferably cyclohexane-1,1-diyl, O, S, SO, SO₂, or CO.

Preferably, the repeating unit represented by Chemical Formula 1 may bederived from one or more aromatic diol compounds selected from the groupconsisting of bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether,bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide,bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone,1,1-bis(4-hydroxyphenyl)ethane, bisphenol A,2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane,2,2-bis(4-hydroxy-3,5-dibromophenyl)propane,2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane,2,2-bis(4-hydroxy-3-bromophenyl)propane,2,2-bis(4-hydroxy-3-chlorophenyl)propane,2,2-bis(4-hydroxy-3-methylphenyl)propane,2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane,1,1-bis(4-hydroxyphenyl)-1-phenylethane,bis(4-hydroxyphenyl)diphenylmethane, andα,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethylsiloxane.

As used herein, ‘derived from aromatic diol compounds’ means that ahydroxy group of the aromatic diol compound and a carbonate precursorare reacted to form the repeating unit represented by Chemical Formula1.

For example, when bisphenol A, i.e., an aromatic diol compound, andtriphosgene, i.e., a carbonate precursor, are polymerized, the repeatingunit represented by Chemical Formula 1 is represented by the followingChemical Formula 1-1:

As the carbonate precursor, one or more selected from the groupconsisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate,dicyclohexyl carbonate, diphenyl carbonate, ditolyl carbonate,bis(chlorophenyl)carbonate, di-m-cresyl carbonate, dinaphthyl carbonate,bis(diphenyl) carbonate, phosgene, triphosgene, diphosgene, bromophosgene, and bishaloformate may be used. Preferably, triphosgene orphosgene may be used.

Meanwhile, the copolycarbonate resin may further include the repeatingunits represented by Chemical Formulae 3 and 4, wherein the repeatingunits represented by Chemical Formulae 3 and 4, which have a specificpolyorganosiloxane structure, may be introduced in the copolycarbonateresin to improve various physical properties such as chemicalresistance, low-temperature impact strength, the YI value, and the like.

In Chemical Formula 3, each of X₁ may be independently preferably C₂₋₁₀alkylene, more preferably C₂₋₄ alkylene, and most preferablypropane-1,3-diyl.

Further, preferably, each of R₁₃ may be independently hydrogen, methyl,ethyl, propyl, 3-phenylpropyl, 2-phenylpropyl,3-(oxiranylmethoxy)propyl, fluoro, chloro, bromo, iodo, methoxy, ethoxy,propoxy, allyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, phenyl, ornaphthyl. In addition, each of R₁₃ may be independently preferably C₁₋₁₀alkyl, more preferably C₁₋₆ alkyl, still more preferably C₁₋₃ alkyl, andmost preferably methyl.

Further, preferably, n may be an integer of 10 or more, 15 or more, 20or more, 25 or more, 30 or more, 31 or more, or 32 or more; and not morethan 50, not more than 45, not more than 40, not more than 39, not morethan 38, or not more than 37.

In Chemical Formula 4, each of X₂ may be independently preferably C₂₋₁₀alkylene, more preferably C₂₋₆ alkylene, and most preferablyisobutylene.

In addition, preferably, Y₁ may be hydrogen.

Further, preferably, each of R₁₄ may be independently hydrogen, methyl,ethyl, propyl, 3-phenylpropyl, 2-phenylpropyl,3-(oxiranylmethoxy)propyl, fluoro, chloro, bromo, iodo, methoxy, ethoxy,propoxy, allyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, phenyl, ornaphthyl. In addition, each of R₁₄ may be independently preferably C₁₋₁₀alkyl, more preferably C₁₋₆ alkyl, still more preferably C₁₋₃ alkyl, andmost preferably methyl.

Further, preferably, m may be an integer of 40 or more, 45 or more, 50or more, 55 or more, 56 or more, 57 or more, or 58 or more; and not morethan 80, not more than 75, not more than 70, not more than 65, not morethan 64, not more than 63, or not more than 62.

The repeating unit represented by Chemical Formula 3 and the repeatingunit represented by Chemical Formula 4 may be derived from a siloxanecompound represented by Chemical Formula 3-1 and a siloxane compoundrepresented by Chemical Formula 4-1, respectively.

in Chemical Formula 3-1,

X₁, R₁₃, and n are as previously defined.

in Chemical Formula 4-1,

X₂, Y₁, R₁₄, and m are as previously defined.

As used herein, ‘derived from a siloxane compound’ means that a hydroxygroup of each of the siloxane compounds and a carbonate precursor arereacted to form the repeating unit represented by Chemical Formula 3 andthe repeating unit represented by the Chemical Formula 4. Further,descriptions of the carbonate precursors that may be used for theformation of the repeating units represented by Chemical Formulae 3 and4 are the same as those described for the carbonate precursor that canbe used for the formation of the repeating unit represented by ChemicalFormula 1 described above.

The methods for preparing the siloxane compound represented by ChemicalFormula 3-1 and the siloxane compound represented by Chemical Formula4-1 are represented by the following Reaction Schemes 1 and 2,respectively:

in Reaction Scheme 1,

X₁′ is C₂₋₁₀ alkenyl, and

X₁, R₁₃, and n are as previously defined,

in Reaction Scheme 2,

X₂′ is C₂₋₁₀ alkenyl, and

X₂, Y₁, R₁₄, and m are as previously defined.

In Reaction Scheme 1 and Reaction Scheme 2, the reaction may bepreferably conducted in the presence of a metal catalyst. As the metalcatalyst, a Pt catalyst may be preferably used. The Pt catalyst usedherein may include one or more selected from the group consisting ofAshby catalyst, Karstedt catalyst, Lamoreaux catalyst, Speier catalyst,PtCl₂ (COD), PtCl₂(benzonitrile)₂, and H₂PtBr₆. The metal catalyst maybe used in an amount of 0.001 parts by weight or more, 0.005 parts byweight or more, or 0.01 parts by weight or more; and not more than 1part by weight, not more than 0.1 part by weight, or not more than 0.05part by weight, based on 100 parts by weight of compounds represented bythe Chemical Formula 7 or 9.

Further, a reaction temperature is preferably 80 to 100° C. Further, areaction time is preferably 1 to 5 hours.

In addition, the compound represented by Chemical Formula 7 or 9 may beprepared by reacting an organodisiloxane and an organocyclosiloxane inthe presence of an acid catalyst, and n and m may be adjusted byadjusting amounts of the reactants. A reaction temperature is preferably50 to 70° C. Further, a reaction time is preferably 1 to 6 hours.

As the organodisiloxane, one or more selected from the group consistingof tetramethyldisiloxane, tetraphenyldisiloxane, hexamethyldisiloxane,and hexaphenyldisiloxane may be used. In addition, as theorganocyclosiloxane, for example, organocyclotetrasiloxane may be used.Examples of the organocyclotetrasiloxane may includeoctamethylcyclotetrasiloxane, octaphenylcyclotetrasiloxane, and thelike.

The organodisiloxane may be used in an amount of 0.1 parts by weight ormore, or 2 parts by weight or more; and not more than 10 parts by weightor not more than 8 parts by weight, based on 100 parts by weight of theorganocyclosiloxane.

As the acid catalyst, one or more selected from the group consisting ofH₂SO₄, HClO₄, AlCl₃, SbCl₅, SnCl₄ and acid clay (fuller's earth) may beused. Further, the acid catalyst may be used in an amount of 0.1 partsby weight or more, 0.5 parts by weight or more, or 1 part by weight ormore; and not more than 10 parts by weight, not more than 5 parts byweight, or not more than 3 parts by weight, based on 100 parts by weightof the organocyclosiloxane.

Physical properties such as chemical resistance, impact resistance, theYI value, and the like, may be simultaneously and suitably improved byadjusting the amounts of the repeating units represented by ChemicalFormulae 3 and 4, simultaneously included in the copolycarbonate resin.To this end, a weight ratio between the repeating units represented byChemical Formulae 3 and 4 may be from 1:99 to 99:1. Preferably, theweight ratio is from 3:97 to 97:3, from 5:95 to 95:5, from 10:90 to90:10, or from 15:85 to 85:15, and more preferably from 20:80 to 80:20.The weight ratio of the repeating units may correspond to a weight ratioof siloxane compounds, for example, the siloxane compound represented byChemical Formula 3-1 and the siloxane compound represented by ChemicalFormula 4-1.

Preferably, the repeating unit represented by Chemical Formula 3 may berepresented by the following Chemical Formula 3-2:

In Chemical Formula 3-2, R₁₃ and n are as previously defined.Preferably, R₁₃ may be methyl.

In addition, preferably, the repeating unit represented by ChemicalFormula 4 may be represented by the following Chemical Formula 4-2:

In Chemical Formula 4-2, R₁₄ and m are as previously defined.Preferably, R₁₄ may be methyl.

In addition, the above-mentioned copolycarbonate resin may include eachof the repeating units represented by Chemical Formulae 1, 3, and 4 sothat a weight ratio of the repeating unit represented by ChemicalFormula 1 and a sum of weights of the repeating unit represented byChemical Formula 3 and the repeating unit represented by ChemicalFormula 4 is from 1:0.001 to 1:0.5, preferably, from 1:0.005 to 1:0.3,and more preferably, from 1:0.01 to 1:0.2. The weight ratio of therepeating units may correspond to a weight ratio of the aromatic diolcompound used to form the repeating unit represented by Chemical Formula1 and the siloxane compounds used to form the repeating unit representedby Chemical Formula 3 and the repeating unit represented by ChemicalFormula 4.

As the copolycarbonate resin includes each of the repeating units at theabove-mentioned weight ratio, the copolycarbonate resin and the resincomposition according to the exemplary embodiment may have excellentlow-temperature impact strength, chemical resistance and low YI values,and a synergic effect with a first polycarbonate resin to be describedbelow may also be optimized, such that the resin composition accordingto the exemplary embodiment may have more excellent flowability andthin-film moldability.

Preferably, the copolycarbonate resin including the repeating unitsrepresented by Chemical Formulae 1, 3, and 4 may be a random copolymer.In addition, the copolycarbonate resin as described above may beprepared by a preparation method including the step of polymerizing twoor more aromatic diol compounds corresponding to the respectiverepeating units, a carbonate precursor, and two or more siloxanecompounds. The aromatic diol compounds, the carbonate precursor, and thesiloxane compounds are the same as previously described.

At the time of the polymerization, the siloxane compounds may be used inan amount of 0.1 wt % or more, 0.5 wt % or more, 1 wt % or more, or 1.5wt % or more; and not more than 20 wt %, not more than 10 wt %, not morethan 7 wt %, not more than 5 wt %, not more than 4 wt %, not more than 3wt %, or not more than 2 wt %, based on 100 wt % in total of thearomatic diol compounds, the carbonate precursor, and the siloxanecompounds.

Further, the aromatic diol compounds may be used in an amount of 40 wt %or more, 50 wt % or more, or 55 wt % or more; and not more than 80 wt %,not more than 70 wt %, or not more than 65 wt %, based on 100 wt % intotal of the aromatic diol compounds, the carbonate precursor, and thesiloxane compounds.

The carbonate precursor may be used in an amount of 10 wt % or more, 20wt % or more, or 30 wt % or more; and not more than 60 wt %, not morethan 50 wt %, or not more than 40 wt %, based on 100 wt % in total oftwo aromatic diol compounds, the carbonate precursor, and the siloxanecompounds.

Further, as a polymerization method, an interfacial polymerizationmethod may be used as one example. In this case, the polymerizationreaction may be carried out at a low temperature under an atmosphericpressure, and it may be easy to control a molecular weight. Theinterfacial polymerization may be preferably conducted in the presenceof an acid binder and an organic solvent. Furthermore, the interfacialpolymerization may include, for example, the steps of conductingpre-polymerization, then adding a coupling agent and conductingpolymerization again. In this case, a copolycarbonate having a highmolecular weight may be obtained.

The materials used in the interfacial polymerization are notparticularly limited as long as they may be used in polymerization ofpolycarbonates. The used amount thereof maybe controlled as required.

The acid binder may include, for example, alkali metal hydroxides suchas sodium hydroxide, potassium hydroxide, or the like, or aminecompounds such as pyridine, or the like.

The organic solvent is not particularly limited as long as it is asolvent that can be usually used in the polymerization ofpolycarbonates. As one example, halogenated hydrocarbon such asmethylene chloride or chlorobenzene, or the like, may be used.

Further, during the interfacial polymerization, a reaction accelerator,for example, a tertiary amine compound such as triethylamine,tetra-n-butylammonium bromide, tetra-n-butylphosphonium bromide, or thelike, a quaternary ammonium compound, a quaternary phosphonium compound,or the like, may be further used for accelerating the reaction.

In the interfacial polymerization, a reaction temperature may bepreferably from 0 to 40° C. and a reaction time may be preferably from10 minutes to 5 hours. Further, during the interfacial polymerizationreaction, pH may be preferably maintained at 9 or more, or 11 or more.

In addition, during the interfacial polymerization reaction, a molecularweight modifier may be additionally used. The molecular weight modifiermay be added before the initiation of polymerization, during theinitiation of polymerization, or after the initiation of polymerization.

As the molecular weight modifier, mono-alkyl phenol may be used. As oneexample, the mono-alkyl phenol may be one or more selected from thegroup consisting of p-tert-butyl phenol, p-cumyl phenol, decyl phenol,dodecyl phenol, tetradecyl phenol, hexadecyl phenol, octadecyl phenol,eicosyl phenol, docosyl phenol and triacontyl phenol. Preferably, themono-alkyl phenol may be p-tert-butyl phenol. In this case, the effectof adjusting the molecular weight control may be great.

The molecular weight modifier may be included, for example, in an amountof 0.01 parts by weight or more, 0.1 parts by weight or more, or 1 partby weight; and not more than 10 parts by weight, not more than 6 partsby weight, or not more than 5 parts by weight, based on 100 parts byweight of the aromatic diol compound. The required molecular weight maybe obtained within the range as described above.

Meanwhile, the above-mentioned copolycarbonate resin may have a weightaverage molecular weight (g/mol) of 1,000 to 100,000. More preferably,the weight average molecular weight may be 15,000 or more, 16,000 ormore, 17,000 or more, 18,000 or more, 19,000 or more, 20,000 or more,21,000 or more, 22,000 or more, 23,000 or more, 24,000 or more, or25,000 or more; and not more than 40,000, not more than 39,000, not morethan 38,000, not more than 37,000, not more than 36,000, not more than35,000, or not more than 34,000.

(2) First Polycarbonate Resin

The resin composition according to the exemplary embodiment may includethe first polycarbonate resin including the repeating unit representedby Chemical Formula 2, having aliphatic alkylene A and further includingthe repeating unit represented by Chemical Formula 1, as needed,together with the above-mentioned copolycarbonate resin. As the firstpolycarbonate resin as described above includes the repeating unitrepresented by Chemical Formula 2, having the aliphatic group, thisresin and the resin composition according the exemplary embodimentcomprising the same may have high flowability, processability, thin-filmmoldability, and the like.

Since a description of the repeating unit represented by ChemicalFormula 1, selectively included in this first polycarbonate resin isprovided above in the description of the copolycarbonate resin, adetailed description thereof will be omitted.

Meanwhile, the first polycarbonate resin may essentially include therepeating unit represented by Chemical Formula 2, which may distinguishthe first polycarbonate resin from a second polycarbonate resin to bedescribed below, that is, a general aromatic polycarbonate resin. InChemical Formula 2, preferably, R₅ to R₁₂ may be each independentlyhydrogen, methyl, chloro, or bromo. In addition, preferably, R₅ to R₁₂may be the same as each other.

Further, preferably, Z₁ and Z₂ may be each independently a linear orbranched C₁₋₁₀ alkylene unsubstituted or substituted with phenyl. Morepreferably, Z₁ and Z₂ may be each independently methylene,ethane-1,1-diyl, propane-2,2-diyl, butane-2,2-diyl,1-phenylethane-1,1-diyl or diphenylmethylene. In addition, preferably,Z₁ and Z₂ may be each independently cyclohexane-1,1-diyl, O, S, SO, SO₂,or CO. Further, preferably, Z₁ and Z₂ may be the same as each other.

Furthermore, preferably, A may be a linear or branched C₁₋₁₀ alkylene.In addition, A may be preferably a linear C₁₋₁₀ alkylene, morepreferably, a linear C₃₋₉ alkylene, and most preferably, octylene.

More specifically, the repeating unit represented by Chemical Formula 2may be represented by Chemical Formula 2-1:

The repeating unit represented by Chemical Formula 2 may be formed by areaction of an aromatic diol compound represented by the followingChemical Formula 2-2 and a carbonate precursor.

In Chemical Formula 2-2, R₅ to R₁₂, Z₂, Z₃, and A are as previouslydefined.

A description of the carbonate precursor that may be used for theformation of the repeating unit represented by Chemical Formula 2 is thesame as that described for the carbonate precursor that can be used forthe formation of the repeating unit represented by Chemical Formula 1described above.

The first polycarbonate resin may include the repeating unit representedby Chemical Formula 1 and the repeating unit represented by ChemicalFormula 2 so as to have a weight ratio of preferably from 1:0.001 to1:0.3, more preferably from 1:0.004 to 1:0.15, and most preferably from1:0.01 to 1:0.1. The first polycarbonate resin may have suitablemechanical properties and high flowability within the above-mentionedrange. The weight ratio may correspond to a weight ratio of the aromaticdiol compounds used to form the repeating units represented by ChemicalFormulae 1 and 2.

Meanwhile, the above-mentioned first polycarbonate resin may have aweight average molecular weight (g/mol) of 1,000 to 100,000. Morepreferably, the weight average molecular weight may be 15,000 or more,16,000 or more, 17,000 or more, 18,000 or more, 19,000 or more, 20,000or more, 21,000 or more, 22,000 or more, 23,000 or more, 24,000 or more,or 25,000 or more; and not more than 40,000, not more than 39,000, notmore than 38,000, not more than 37,000, not more than 36,000, not morethan 35,000, or not more than 34,000.

In the polycarbonate based resin composition according to the exemplaryembodiment, contents of the copolycarbonate resin and the firstpolycarbonate resin may be changed depending on physical properties of acomposition to be adjusted. For example, the content of thecopolycarbonate resin included in the resin composition according to theexemplary embodiment may be from 1 to 99 wt %, from 10 to 90 wt %, from30 to 70 wt %, or from 40 to 60 wt %, based on 100 wt % of the entireresin composition according to the exemplary embodiment, and the contentof the first polycarbonate resin may be the rest except for the contentof the copolycarbonate resin, for example, from 1 to 99 wt %, from 10 to90 wt %, from 30 to 70 wt %, or from 40 to 60 wt %, based on 100 wt % ofthe resin composition according to the exemplary embodiment.

Therefore, flowability and processability (thin-film moldability),impact strength such as low-temperature impact strength, or the like,chemical resistance, the YI value, and the like, of the resincomposition according to the exemplary embodiment may be optimized.However, in the case in which an excessive content of thecopolycarbonate resin is added, transparency of the resin compositionmay be deteriorated, or flowability may not be sufficient, and an effectof improving heat resistance and impact strength may reach a criticalvalue or be rather deteriorated. Further, in the case in which anexcessive content of the first polycarbonate resin is added, impactstrength, chemical resistance, and the like, of the resin compositionmay not be sufficient.

Meanwhile, the resin composition according to the exemplary embodimentmay further include a second polycarbonate resin corresponding to ageneral aromatic polycarbonate resin which does not include therepeating units represented by Chemical Formulae 2 to 4 but includesonly the repeating unit represented by Chemical Formula 1. The secondpolycarbonate resin as described above may be distinguished from thecopolycarbonate resin and the first polycarbonate resin by the fact thatthe second polycarbonate resin does not include the repeating unitsrepresented by Chemical Formulae 2 to 4.

The repeating unit represented by Chemical Formula 1, included in thesecond polycarbonate resin may have a structure equal to or differentfrom the repeating unit represented by Chemical Formula 1 within thesame category, included in the copolycarbonate resin and the firstpolycarbonate resin described above.

Since a description of the repeating unit represented by ChemicalFormula 1 is provided above in the description of the copolycarbonateresin, the second polycarbonate resin corresponding to the generalaromatic polycarbonate resin including the repeating unit represented byChemical Formula 1 may be prepared and provided by a method well-knownto those skilled in the art, an additional description thereof will beomitted.

A suitable content of the second polycarbonate resin as described abovemay be added to the resin composition according to the exemplaryembodiment by those skilled in the art depending on the desired physicalproperties or purposes. However, the second polycarbonate resin may beincluded in a content range of 5 to 100 parts by weight based on 100parts by weight of a sum of the copolycarbonate resin and the firstpolycarbonate resin described above, so as not to inhibit excellentphysical properties and effects of the resin composition according tothe exemplary embodiment obtained by including the copolycarbonate resinand the first polycarbonate resin.

Room-temperature impact strength of the above-mentioned resincomposition according to the exemplary embodiment measured in accordancewith ASTM D256 (⅛ inch, Notched Izod) at 23° C. may be from 500 to 1100J/m. More preferably, the room-temperature impact strength (J/m) may be650 or more, 700 or more, or 750 or more. In addition, the higher theroom-temperature impact strength (J/m), the more excellent, such thatthere is no upper limit in the room-temperature impact strength (J/m),but the room-temperature impact strength (J/m) may be, for example, notmore than 1050, or not more than 1000.

In addition low-temperature impact strength of the resin compositionaccording to the exemplary embodiment measured in accordance with ASTMD256 (⅛ inch, Notched Izod) at −30° C. may be from 350 to 1,000 J/m.More preferably, the low-temperature impact strength (J/m) may be 450 ormore, 550 or more, 650 or more, or 680 or more. In addition, the higherthe low-temperature impact strength (J/m), the more excellent, such thatthere is no upper limit in the low-temperature impact strength (J/m),but the low-temperature impact strength (J/m) may be, for example, notmore than 990, or not more than 980.

A YI value of the resin composition according to the exemplaryembodiment measured in accordance with ASTM D1925 may be not more than3. More preferably, the YI value may be not more than 2.5, not more than2, not more than 1.99, or not more than 1.98. In addition, since thelower the YI value, the more excellent, there is no lower limit in theYI value, but for example, the YI value may be 0.5 or more, 1 or more or1.5 or more.

In addition, flowability of the resin composition according to theexemplary embodiment measured in accordance with ASTM D 1238 (300° C.,1.2 kg condition) may be from 5 to 20 g/10 min. More preferably, theflowability (g/10 min) may be 5.5 or more, 6 or more, or 6.5 or more;and not more than 19, not more than 18, not more than 17, not more than16, not more than 15, or not more than 14.

Meanwhile, another exemplary embodiment of the present inventionprovides molded articles containing the polycarbonate based resincomposition according to the exemplary embodiment described above.

Preferably, the molded articles may be injection-molded articles. Inaddition, the molded articles may further include, for example, one ormore additives selected from the group consisting of antioxidants, heatstabilizers, light stabilizers, plasticizers, antistatic agents,nucleating agents, flame retardants, lubricants, impact reinforcingagents, fluorescent brightening agents, ultraviolet absorbers, pigments,and dyes.

A method for preparing the molded article may include the steps ofmixing the resin composition according to the exemplary embodiment andadditives such as antioxidants, or the like, using a mixer,extrusion-molding the mixture with an extruder to produce a pellet,drying the pellet and then injecting the dried pellet with an injectionmolding machine.

Advantageous Effects

As set forth above, according to an embodiment of the present invention,the polycarbonate based resin composition of which flowability(fluidity), processability, thin-film moldability and the like, inaddition to impact strength, chemical resistance, and the YI value areimproved, and molded articles thereof may be provided.

MODE FOR INVENTION

Hereinafter, preferable Examples of the present invention will beprovided for better understanding of the present invention. However, thefollowing Examples are provided only for illustration of the presentinvention, and should not be construed as limiting the present inventionby the examples.

Preparation Example 1: Preparation of Polyorganosiloxane AP-30

After 42.5 g (142.8 mmol) of octamethylcyclotetrasiloxane and 2.26 g(16.8 mmol) of tetramethyldisiloxane were mixed with each other, themixture was placed in a 3 L flask with 1 part by weight of acid clay(DC-A3) based on 100 parts by weight of octamethylcyclotetrasiloxane,and reacted at 60° C. for 4 hours. After the reaction was terminated,the reaction product was diluted with ethylacetate and quickly filteredusing a celite. A repeating unit (n) of the unmodifiedpolyorganosiloxane obtained as described above was 30 when confirmedthrough ¹H NMR.

9.57 g (71.3 mmol) of 2-allylphenol and 0.01 g (50 ppm) of Karstedt'splatinum catalyst were added to the obtained terminal-unmodifiedpolyorganosiloxane and reacted at 90° C. for 3 hours. After the reactionwas terminated, the unreacted polyorganosiloxane was removed byevaporation at 120° C. and 1 torr. The terminal-modifiedpolyorganosiloxane obtained as described above was designated as AP-30.AP-30 was pale yellow oil, the repeating unit(n) was 30 when confirmedthrough ¹HNMR using Varian 500 MHz, and further purification was notrequired.

Preparation Example 2: Preparation of Polyorganosiloxane MB-60

After 47.60 g (160 mmol) of octamethylcyclotetrasiloxane and 1.5 g (11mmol) of tetramethyldisiloxane were mixed with each other, the mixturewas placed in a 3 L flask together with 1 part by weight of acid clay(DC-A3) based on 100 parts by weight of octamethylcyclotetrasiloxane,and reacted at 60° C. for 4 hours. After the reaction was terminated,the reaction product was diluted with ethylacetate and quickly filteredusing a celite. A repeating unit (n) of the terminal-unmodifiedpolyorganosiloxane obtained as described above was 60 when confirmedthrough ¹H NMR.

6.13 g (29.7 mmol) of 3-methylbut-3-enyl 4-hydroxybenzoate and 0.01 g(50 ppm) of Karstedt's platinum catalyst were added to the obtainedterminal-unmodified polyorganosiloxane and reacted at 90° C. for 3hours. After the reaction was terminated, the unreactedpolyorganosiloxane was removed by evaporation at 120° C. and 1 torr. Theterminal-modified polyorganosiloxane obtained as described above wasdesignated as MB-60. MB-60 was pale yellow oil, the repeating unit (m)was 60 when confirmed through ¹HNMR using Varian 500 MHz, and furtherpurification was not required.

Preparation Example 3: Preparation 1 of Copolycarbonate Resin

After placing 979.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP),79.3179 g of previously prepared polyorganosiloxane (AP-30), and 8.8191g of polyorganosiloxane (MB-60) of Preparation Example 2 were addedthereto and mixed therewith (9 wt % of polyorganosiloxanes (AP-30+MB-60)were used based on BPA; repeating units represented by Chemical Formulae1, 3, and 4 were formed so as to have contents corresponding thereto).3,850 g of methylene chloride in which 542.5 g of triphosgene wasdissolved was added thereto dropwise for 1 hour. In this case, a PH ofthe aqueous NaOH solution was maintained at 12. After the dropwiseaddition was completed, the mixture was aged for 15 minutes, and 195.7 gof triethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a copolycarbonate resin (Mw:34000) as powder.

Preparation Example 4: Preparation 2 of Copolycarbonate Resin

After placing 979.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP),83.7814 g of previously prepared polyorganosiloxane (AP-30), and 4.4096g of polyorganosiloxane (MB-60) of Preparation Example 2 were addedthereto and mixed therewith (9 wt % of polyorganosiloxanes (AP-30+MB-60)were used based on BPA; repeating units represented by Chemical Formulae1, 3, and 4 were formed so as to have contents corresponding thereto).3,850 g of methylene chloride in which 542.5 g of triphosgene wasdissolved was added thereto dropwise for 1 hour. In this case, a PH ofthe aqueous NaOH solution was maintained at 12. After the dropwiseaddition was completed, the mixture was aged for 15 minutes, and 195.7 gof triethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a copolycarbonate resin (Mw:34000) as powder.

Preparation Example 5: Preparation 3 of Copolycarbonate Resin

After placing 979.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP),52.914 g of previously prepared polyorganosiloxane (AP-30), and 5.88 gof polyorganosiloxane (MB-60) of Preparation Example 2 were addedthereto and mixed therewith (6 wt % of polyorganosiloxanes (AP-30+MB-60)were used based on BPA; repeating units represented by Chemical Formulae1, 3, and 4 were formed so as to have contents corresponding thereto).3,850 g of methylene chloride in which 542.5 g of triphosgene wasdissolved was added thereto dropwise for 1 hour. In this case, a PH ofthe aqueous NaOH solution was maintained at 12. After the dropwiseaddition was completed, the mixture was aged for 15 minutes, and 195.7 gof triethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a copolycarbonate resin (Mw:34000) as powder.

Preparation Example 6: Preparation 4 of Copolycarbonate Resin

After placing 979.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP), and88.191 g of previously prepared polyorganosiloxane (AP-30) were addedthereto and mixed therewith (9 wt % of polyorganosiloxane (AP-30) wasused based on BPA; repeating units represented by Chemical Formulae 1and 3 were formed so as to have contents corresponding thereto). 3,850 gof methylene chloride in which 542.5 g of triphosgene was dissolved wasadded thereto dropwise for 1 hour. In this case, a PH of the aqueousNaOH solution was maintained at 12. After the dropwise addition wascompleted, the mixture was aged for 15 minutes, and 195.7 g oftriethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a copolycarbonate resin (Mw:34000) as powder.

Preparation Example 7: Preparation 1 of First Polycarbonate Resin

After placing 976.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP), and7.81 g of previously preparedbis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) decanedioate (BPDA) wereadded thereto and mixed therewith (0.8 wt % of BPDA was used based onBPA; repeating units represented by Chemical Formulae 1 and 2 wereformed so as to have contents corresponding thereto). 3,850 g ofmethylene chloride in which 542.5 g of triphosgene was dissolved wasadded thereto dropwise for 1 hour. In this case, a PH of the aqueousNaOH solution was maintained at 12. After the dropwise addition wascompleted, the mixture was aged for 15 minutes, and 195.7 g oftriethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a polycarbonate resin (Mw:34000) as powder.

Preparation Example 8: Preparation 2 of First Polycarbonate Resin

After placing 968.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP), and29.32 g of previously preparedbis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) decanedioate (BPDA) wereadded thereto and mixed therewith (3.0 wt % of BPDA was used based onBPA; repeating units represented by Chemical Formulae 1 and 2 wereformed so as to have contents corresponding thereto). 3,850 g ofmethylene chloride in which 542.5 g of triphosgene was dissolved wasadded thereto dropwise for 1 hour. In this case, a PH of the aqueousNaOH solution was maintained at 12. After the dropwise addition wascompleted, the mixture was aged for 15 minutes, and 195.7 g oftriethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a polycarbonate resin (Mw:34000) as powder.

Preparation Example 9: Preparation 3 of First Polycarbonate Resin

After placing 943.7 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride, 17.9 g of p-tert-butylphenol (PTBP), and96.34 g of previously preparedbis(4-(2-(4-hydroxyphenyl)propan-2-yl)phenyl) decanedioate (BPDA) wereadded thereto and mixed therewith (10.0 wt % of BPDA was used based onBPA; repeating units represented by Chemical Formulae 1 and 2 wereformed so as to have contents corresponding thereto). 3,850 g ofmethylene chloride in which 542.5 g of triphosgene was dissolved wasadded thereto dropwise for 1 hour. In this case, a PH of the aqueousNaOH solution was maintained at 12. After the dropwise addition wascompleted, the mixture was aged for 15 minutes, and 195.7 g oftriethylamine was dissolved in methylene chloride and added thereto.After 10 minutes, a pH was adjusted to 3 with 1N aqueous hydrochloricacid solution, and then the resultant was washed with distilled waterthree times. Thereafter, a methylene chloride phase was separated, andprecipitated in methanol, thereby obtaining a polycarbonate resin (Mw:34000) as powder.

Preparation Example 10: Preparation 4 of Polycarbonate Resin

After placing 979.9 g of bisphenol A (BPA), 1,620 g of 32% aqueous NaOHsolution, and 7,500 g of distilled water in a 20 L glass reactor andconfirming that BPA was completely dissolved under nitrogen atmosphere,3,670 g of methylene chloride and 17.9 g of p-tert-butylphenol (PTBP)were added thereto and mixed therewith. 3,850 g of methylene chloride inwhich 542.5 g of triphosgene was dissolved was added thereto dropwisefor 1 hour. In this case, a PH of the aqueous NaOH solution wasmaintained at 12. After the dropwise addition was completed, the mixturewas aged for 15 minutes, and 195.7 g of triethylamine was dissolved inmethylene chloride and added thereto. After 10 minutes, a pH wasadjusted to 3 with 1N aqueous hydrochloric acid solution, and then theresultant was washed with distilled water three times. Thereafter, amethylene chloride phase was separated, and precipitated in methanol,thereby obtaining a polycarbonate resin (Mw: 34000) as powder.

Examples 1 to 5 and Comparative Examples 1 to 5: Preparation ofPolycarbonate Based Resin Composition and Molded Articles Thereof

The copolycarbonate resin and the polycarbonate resin were mixedaccording to the composition illustrated in the following Table 1.Additionally, based on 1 part by weight of the resin mixture, 0.050parts by weight of tris(2,4-di-tert-butylphenyl)phosphite, 0.010 partsby weight of octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,and 0.030 parts by weight of pentaerythritoltetrastearate were addedthereto, and the resulting mixture was pelletized using a φ30 mmtwin-screw extruder provided with a vent, and was injection-molded at acylinder temperature of 300° C. and a mold temperature of 80° C. using aN-20C injection-molding machine (JSW Co.), thereby preparing a desiredspecimen.

TABLE 1 Comparative Comparative Comparative Comparative ComparativeExample 1 Example 2 Example 3 Example 4 Example 5 Example 1 Example 2Example 3 Example 4 Example 5 Co-PC Prepara- Preparation PreparationPreparation Preparation X Preparation X Preparation Preparation Resin*tion Example 3 Example 3 Example 4 Example 5 (0) Example 3 (0) Example 6Example 6 (wt %) Example 3 (50) (50) (50) (50) (100) (100) (50) (50)First PC Prepara- Preparation Preparation Preparation PreparationPreparation X Preparation X Preparation resin* tion Example 8 Example 9Example 8 Example 8 Example (0) Example 9 (0) Example 9 (wt %) Example 7(50) (50) (50) (50) 10* (100) (50) (50) (100) *Co-PC Resin:Copolycarbonate resin *First PC resin: first polycarbonate resin*Preparation Example 10: Since the specimen was prepared without usingBPDA, the specimen did not correspond to the first polycarbonate resin,but corresponded to a general polycarbonate resin (corresponding to thesecond polycarbonate resin).

Experimental Example: Confirm of Characteristics of Polycarbonate BasedResin Composition and Injected Specimen

Weight average molecular weights of the copolycarbonate resins and thepolycarbonate resins prepared in Examples and Comparative Examples weremeasured by GPC using PC standard and Agilent 1200 series.

In addition, physical properties of the compositions and injectionspecimens obtained in Examples and Comparative Examples were measured bythe following methods, and the results were illustrated in the followingTable 2.

1) Room-Temperature Impact Strength: measured at 23° C. in accordancewith ASTM D256 (⅛ inch, Notched Izod).

2) Low-Temperature Impact Strength: measured at −30° C. in accordancewith ASTM D256 (⅛ inch, Notched Izod).

3) YI (Yellow Index): Specimen (width/length/thickness=60 mm/40 mm/3 mm)was injection-molded at 300° C., and then YI (Yellow Index) was measuredunder the following conditions by using Color-Eye 7000A (X-rite Inc.) inaccordance with ASTM D1925.

-   -   Measurement temperature: room temperature (23° C.)    -   Aperture size: Large area of view

Measurement method: transmittance was measured in a spectral range (360nm to 750 nm)

-   -   4) Flowability (MI): measured in accordance with ASTM D1238        (300° C., 1.2 kg condition).

TABLE 2 Room-Temperature Low-temperature Impact Strength Impact StrengthMI (J/m) (J/m) YI (g/10 min) Example 1 980 900 1.98 6.8 Example 2 900830 1.98 7.1 Example 3 830 810 1.95 12.2 Example 4 845 780 1.96 6.8Example 5 800 680 1.94 8.1 Comparative 950 190 1.75 5.7 Example 1Comparative 1090 980 6.8 3.1 Example 2 Comparative 820 230 0.93 15.9Example 3 Comparative 800 520 6.3 4.3 Example 4 Comparative 720 460 1.9810.9 Example 5

Referring to Table 2, it was confirmed that in Examples 1 to 5, highroom-temperature impact strength and low-temperature impact strength, alow YI value, and relatively high flowability (MI) were simultaneouslyexhibited. On the contrary, it was confirmed that in ComparativeExamples 1, 3, and 5, low-temperature impact strength was low.Particularly, as illustrated in Comparative Example 5, it was confirmedthat in a case in which a structure of the copolycarbonate resin wasdifferent from that in Examples, low-temperature impact strength wasdeteriorated.

Further, it was confirmed that in Comparative Examples 2 and 4,flowability was poor, a YI value was high as compared to Examples, andin Comparative Example 4, low-temperature impact strength was also notsufficient.

1. A polycarbonate based resin composition comprising: a copolycarbonateresin including a repeating unit represented by the following ChemicalFormula 1, a repeating unit represented by the following ChemicalFormula 3, and a repeating unit represented by the following ChemicalFormula 4; and a first polycarbonate resin including a repeating unitrepresented by the following Chemical Formula 2:

in Chemical Formula 1, R₁ to R₄ are each independently hydrogen, C₁₋₁₀alkyl, C₁₋₁₀ alkoxy, or halogen, Z₁ is C₁₋₁₀ alkylene unsubstituted orsubstituted with phenyl, C₃₋₁₅ cycloalkylene unsubstituted orsubstituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO,

in Chemical Formula 2, R₅ to R₁₂ are each independently hydrogen, C₁₋₁₀alkyl, C₁₋₁₀ alkoxy, or halogen, Z₂ and Z₃ are each independently C₁₋₁₀alkylene unsubstituted or substituted with phenyl, C₃₋₁₅ cycloalkyleneunsubstituted or substituted with C₁₋₁₀ alkyl, O, S, SO, SO₂, or CO, andA is C₁₋₁₅ alkylene,

in Chemical Formula 3, each of X₁ is independently C₁₋₁₀ alkylene, eachof R₁₃ is independently hydrogen; C₁₋₁₅ alkyl unsubstituted orsubstituted with oxiranyl, oxiranyl-substituted C₁₋₁₀ alkoxy, or C₆₋₂₀aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀ haloalkyl; or C₆₋₂₀ aryl, andn is an integer of 10 to 200,

in Chemical Formula 4, each of X₂ is independently C₁₋₁₀ alkylene, eachof Y₁ is independently hydrogen, C₁₋₆ alkyl, halogen, hydroxy, C₁₋₆alkoxy, or C₆₋₂₀ aryl, each of R₁₄ is independently hydrogen; C₁₋₁₅alkyl unsubstituted or substituted with oxiranyl, oxiranyl-substitutedC₁₋₁₀ alkoxy, or C₆₋₂₀ aryl; halogen; C₁₋₁₀ alkoxy; allyl; C₁₋₁₀haloalkyl; or C₆₋₂₀ aryl, and m is an integer of 10 to
 200. 2. Thepolycarbonate based resin composition of claim 1, wherein: the firstpolycarbonate resin further includes a repeating unit represented byChemical Formula
 1. 3. The polycarbonate based resin composition ofclaim 1, further comprising a second polycarbonate resin including onlya repeating unit represented by Chemical Formula
 1. 4. (canceled)
 5. Thepolycarbonate based resin composition of claim 1, wherein: the repeatingunit represented by Chemical Formula 1 is derived from one or morearomatic diol compounds selected from the group consisting ofbis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether,bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide,bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone,1,1-bis(4-hydroxyphenyl)ethane, bisphenol A,2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane,2,2-bis(4-hydroxy-3,5-dibromophenyl)propane,2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane,2,2-bis(4-hydroxy-3-bromophenyl)propane,2,2-bis(4-hydroxy-3-chlorophenyl)propane,2,2-bis(4-hydroxy-3-methylphenyl)propane,2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane,1,1-bis(4-hydroxyphenyl)-1-phenylethane,bis(4-hydroxyphenyl)diphenylmethane, andα,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethylsiloxane.
 6. Thepolycarbonate based resin composition of claim 1, wherein: the repeatingunit represented by Chemical Formula 1 is represented by the followingChemical Formula 1-1:


7. The polycarbonate based resin composition of claim 1, wherein: R₅ toR₁₂ are each independently hydrogen, methyl, chloro, or bromo.
 8. Thepolycarbonate based resin composition of claim 1, wherein: Z₁ and Z₂ areeach independently a linear or branched C₁₋₁₀ alkylene unsubstituted orsubstituted with phenyl, cyclohexane-1,1-diyl, O, S, SO, SO₂, or CO. 9.The polycarbonate based resin composition of claim 1, wherein: A is alinear C₁₋₁₀ alkylene.
 10. The polycarbonate based resin composition ofclaim 1, wherein: the repeating unit represented by Chemical Formula 2is represented by Chemical Formula 2-1:


11. The polycarbonate based resin composition of claim 2, wherein: thefirst polycarbonate resin includes the repeating unit represented byChemical Formula 1 and the repeating unit represented by ChemicalFormula 2 at a weight ratio of 1:0.001 to 1:0.3.
 12. The polycarbonatebased resin composition of claim 1, wherein: the copolycarbonate resinincludes the respective repeating units so that a weight ratio of therepeating unit represented by Chemical Formula 1 and a sum of weights ofthe repeating units represented by Chemical Formulae 3 and 4 is 1:0.001to 1:0.5.
 13. The polycarbonate based resin composition of claim 1,wherein: the repeating unit represented by Chemical Formula 3 isrepresented by Chemical Formula 3-2:


14. The polycarbonate based resin composition of claim 12, wherein: R₁₃is methyl.
 15. The polycarbonate based resin composition of claim 1,wherein: the repeating unit represented by Chemical Formula 4 isrepresented by Chemical Formula 4-2:


16. The polycarbonate based resin composition of claim 14, wherein: R₁₄is methyl. 17.-18. (canceled)